Configuring External Storage (GUI)

The External Storage Support application enables you to mount external storage services and devices as secondary ownCloud storage devices. You may also allow users to mount their own external storage services.

Enabling External Storage Support


Enabling this app will disable the Stay logged in checkbox on the login page.

The External storage support application is enabled on your Apps page.

Enable external storage on your Apps page.

Storage Configuration

To create a new external storage mount, select an available backend from the dropdown Add storage. Each backend has different required options, which are configured in the configuration fields.


Each backend may also accept multiple authentication methods. These are selected with the dropdown under Authentication. Different backends support different authentication mechanisms; some specific to the backend, others are more generic. See External Storage Authentication mechanisms for more detailed information.

When you select an authentication mechanism, the configuration fields change as appropriate for the mechanism. Some backends are not yet migrated to the new authentication mechanism system, and are displayed with a mechanism of Built-in. The SFTP backend, to give an example, supports both password-based authentication and public key authentication.

An SFTP configuration example.

Required fields are marked with a red border. When all required fields are filled, the storage is automatically saved. A green dot next to the storage row indicates the storage is ready for use. A red or yellow icon indicates that ownCloud could not connect to the external storage, so you need to re-check your configuration and network availability.

If there is an error on the storage, it will be marked as unavailable for ten minutes. To re-check it, click the colored icon or reload your Admin page.

User and Group Permissions

A storage configured in a user’s Personal settings is available only to the user that created it. A storage configured in the Admin settings is available to all users by default, and it can be restricted to specific users and groups in the Available for field.

User and groups selector

Mount Options

Hover your cursor to the right of any storage configuration to expose the settings button and trashcan. Click the trashcan to delete the mountpoint. The settings button allows you to configure each storage mount individually with the following options:

  • Encryption
  • Previews
  • Filesystem check frequency (Never, Once per direct access, every time the filesystem is used)
Additional mount options exposed on mouseover.

Using Self-Signed Certificates

When using self-signed certificates for external storage mounts the certificate must be imported into the personal settings of the user. Please refer to ownCloud HTTPS External Mount for more information.

Available storage backends

The following backends are provided by the external storages app. Other apps may provide their own backends, which are not listed here.


A non-blocking or correctly configured SELinux setup is needed for these backends to work. Please refer to the SELinux Configuration.

Allow Users to Mount External Storage

Check Enable User External Storage to allow your users to mount their own external storage services, and check the backends you want to allow. Beware, as this allows a user to make potentially arbitrary connections to other services on your network!

Checkboxes to allow users to mount external storage services.

Adding Files to External Storages

We recommend configuring the background job Webcron or Cron (see Defining Background Jobs) to enable ownCloud to automatically detect files added to your external storages.

ownCloud may not always be able to find out what has been changed remotely (files changed without going through ownCloud), especially when it’s very deep in the folder hierarchy of the external storage.

You might need to setup a cron job that runs sudo -u www-data php occ files:scan --all (or replace “–all” with the user name, see also Using the occ Command) to trigger a rescan of the user’s files periodically (for example every 15 minutes), which includes the mounted external storage.

Configuration File

Storage mount configurations are stored in a JSON formatted file. Admin storages are stored in data/mount.json, while personal storages are stored in data/$user/mount.json. For more advanced use cases, including provisioning external storages from outside ownCloud, see Configuring External Storage (Configuration File).

All documentation licensed under the Creative Commons Attribution 3.0 Unported license.